1. Field of the Invention
The present invention relates generally to dialysis access, and can be used as an alternative, to A-V Fistula, A-V Graft and external catheters and, more specifically, to an implantable hemodialysis triple port assembly which will provide a cosmetically appealing apparatus for long term dialysis patients, a fault tolerant apparatus for health care professionals who sometimes fail to flush the catheter with a heparinized solution after each use; and relieve overburdened doctors and hospitals from repeated surgery required for creation of arteriovenous fistulas, arteriovenous grafts and the treatment of their complications, such as clotting, usually requiring one to three hospitalizations per patient per year to either declot the graft or fistula or create a new one. The implantable hemodialysis triple port assembly will also eliminate the need for an external dialysis catheter while preventing problems such as frequent clotting, infection and inconvenience to the patient associated therewith.
2. Description of the Prior Art
Hemodialysis acts to purify the blood by passing it through a dialysis machine at a rate of 300-500 cc per minute. In order to perform this procedure two (2) large needles (at least 16G) are required for piercing a vein or graft (called angio-access) of sufficient size to provide an appropriate flow of blood. One needle will act to withdraw blood from the patient for delivery to the dialysis machine and the other needle will act to return the purified blood from the dialysis machine to the patient. Each hemodialysis session usually lasts 2-4 hours and must be performed three times a week over the course of the patient's life.
The veins of the arms are not large enough to accommodate the withdrawal of 300-500 cc of blood per minute extracted by the dialysis machines. Therefore, the veins in the arm must be enlarged by creating a fistula between an artery and vein (A-V Fistula). This may be performed in only a small percentage of dialysis patients due to the small or fibrotic veins associated with renal failure patients making them unsuitable for creation of a fistula. Furthermore, when the fistula has been successfully created a period of 4-8 weeks is needed in order for the fistula to mature before it can be used for dialysis.
A second option for angio access is creating an arterial-venous graft. This is performed using a synthetic tube, requires a patient to remain in the hospital for several days and takes 1-3 weeks before the graft can be used. There is also a high rate of complication due to clotting, infection and arm swelling associated with this procedure. Thus, declotting and frequent replacement of the graft are normally required.
The third option is implanting an external temporary catheter to be used until the A-V Fistula or shunt is ready for use. This procedure also has pitfalls such as inconvenience to the patient as it remains outside the skin, frequent infection and the need for the catheter to be replaced.
Numerous types of devices for aiding in dialysis treatment have been provided in the prior art. For example, U.S. Pat. Nos. 4,846,806; 4,892,518; 4,950,259 and 5,037,385 all are illustrative of such prior art. While these units may be suitable for the particular purpose to which they address, they would not be as suitable for the purposes of the present invention as heretofore described.